In many situations, it is desirable to hold a door in an open position. Devices for this purpose may be utilized with automatic closing features which are used for remotely closing a door when a condition, for example, such as smoke or fire is present and it is desired that a particular entry way be secured. Previously developed door holding devices with automatic closing have utilized electromagnets that are powered continuously during the holding of the door in the open position with the power remotely turn-off to the electromagnet during closed-door periods, which can be short compared to the open-door periods.
In today's more energy efficient buildings, holding multiple doors open 24/7, when using such electromagnets, can over time become a major energy draw for the building's power management system. Thus, a need has arisen for a door holding electromagnet to be unpowered during the holding of the door in the open position to eliminate the continuous power draw on the building's power management system.
Further building power management systems are increasingly converting to green energy, as solar power, to reduce the carbon foot-print of the building. Green energy mechanisms typically have low power inputs that either have to be stored over time before power conversion can be made or the green energy systems have to be large, both can be complex. Thus, a need has arisen for a door holding electromagnet to be powered and controlled by a power versatile circuit to reduce the complexity of the green energy system used by a building's power management system.
Door holding electromagnets are widely used in existing buildings and other facilities. Therefore, there is a need for an energy efficient and power versatile door holding electromagnet that does not substantially change the foot-print of the existing door holding electromagnet system that is being replaced.